This invention relates to a process for the production of a gel, more particularly a food gel, and to the gel obtained by this process.
There are various known processes for modifying starches in which the starches are complexed with an emulsifier, for example to improve their dispersibility or their thickening power.
Thus, U.S. Pat. No. 4,491,483 (Dudacek et al.) describes a starch readily dispersible in boiling water which is obtained by treatment of a native starch at 50.degree. to 120.degree. C. in the presence of 10 to 40% water and at least 0.25%, based on the weight of the starch, of an emulsifier, and drying, the precise conditions of this treatment by exposure to moisture and heat being selected to avoid gelatinization of the starch. The effect of this treatment is to increase the gelatinization temperature of the starch and thus to avoid the formation of lumps when the starch is dispersed in boiling water.
French Patent No. 2 629 684 (INRA) relates to a amylaceous product readily dispersible both in cold and in hot or boiling water which is obtained by microwave treatment of a medium containing a native starch, 30 to 50% water and, optionally, at most 3%, based on the weight of the starch, of an amylose-complexing agent, granulation of the paste thus obtained and drying. The microwave treatment is carried out for 30 s to 15 mins. at 50.degree. to 98.degree. C. until at least 50% of the starch has gelatinized. The amylaceous material thus obtained may be used for its binding properties in the preparation of cooked dishes, cold meats and sauces for example.
European Patent Application Publication No. EP 011 479 (General Foods) describes a process for the production of a pregelatinized modified starch suitable for use in the preparation of instant puddings, in which sodium or calcium stearoyl lactyl-2-lactate and/or a combination of a protein and an emulsifier is added to an aqueous dispersion of native starch and in which either a dispersion is heated and directly dried on rollers to a dry matter content of 20 to 40% or a dispersion is heated in a scraped-surface heat exchanger to a dry matter content of less than 10%, for example 7.2%, and is then spray-dried.
In a variant of the process according to European Patent Application Publication No. 011 479 in which a roller dryer is used, the rollers are heated with steam under a pressure of 3 to 11 bar and are rotated at a speed of a few revolutions per minute. In the variant where a scraped surface heat exchanger is used, the dispersion is preferably preheated to just below the gelatinization temperature of the starch, for example to 65.degree.-70.degree. C. for tapioca, to increase this gelatinization temperature, and is then heated at 80.degree. to 90.degree. C. for a sufficient time to completely gelatinize the starch.
The embodiment of the process according to EP 011 479, in which only sodium or calcium stearoyl lactyl-2-lactate is added, gives a pregelatinized modified starch which has the same thickening effect as an unmodified pregelatinized starch. The actual modification provides the reconstituted pudding with a softer and creamier texture and with a brighter appearance.
There are also various powders for food gels of the instant dessert type or the cooked pudding type which contain starch as a thickener and an emulsifier to smooth the texture of the reconstituted dessert.
Thus, U.S. Pat. No. 3,917,875 (Gardiner) describes a powder for an instant dessert of the yoghurt type which contains sugar, gelatine, a stabilizer, such as a gum, a food acid, pregelatinized starch and, optionally, an emulsifier and/or colouring and flavouring agents.
Similarly, U.S. Pat. No. 4,262,031 (Carpenter et al.) describes a powder for a pudding intended for cooking which contains sugar, non-gelatinized starch, more particularly native cornstarch, highly alkalized cocoa powder, an acidifier and, optionally, an emulsifier and/or a stabilizer, such as a gum.